Hi,
I don't know for how long, but I just checked and discovered today
that there is a similar directory for Icedove that it is for iceweasel
on http://mozilla.debian.net/ called icedove-release. So if you already
have iceweasel-release in your sources.list you just have to add
icedove-release on the end of the line to get the new icedove, so the
line will look like this:
/deb http://mozilla.debian.net/ squeeze-backports iceweasel-release
icedove-release
/If you don't have mozilla.debian repo in yet, just follow instructions
on http://mozilla.debian.net/
Cheers,
Dejan